Photochemistry and Non-adiabatic Photodynamics of the HOSO Radical
6 pags., 2 figs.
Photochemistry of oxidized Hg(I) and Hg(II) species suggests missing mercury oxidation in the troposphere.
8 pags., 5 figs., 2 tabs.
Modelling molecular iodine emissions in a coastal marine environment: The link to new particle formation
International audience; A model of iodine chemistry in the marine boundary layer (MBL) has been used to investigate the impact of daytime coastal emissions of molecular iodine (I2). The model contains a full treatment of gas-phase iodine chemistry, combined with a description of the nucleation and growth, by condensation and coagulation, of iodine oxide nano-particles. In-situ measurements of coastal emissions of I2 made by the broadband cavity ring-down spectroscopy (BBCRDS) and inductively coupled plasma-mass spectrometry (ICP/MS) techniques are presented and compared to long path differential optical absorption spectroscopy (DOAS) observations of I2 at Mace Head, Ireland. Simultaneous me…
Ab initio quantum-chemical computations of the electronic states in HgBr2 and IBr: Molecules of interest on the Earth’s atmosphere
The electronic states of atmospheric relevant molecules IBr and HgBr are reported, within the UV-Vis spectrum range (170nm≤λphoton≤600 nm) by means of the complete-active-space self-consistent field/multi-state complete-active-space second-order perturbation theory/spin-orbit restricted-active-space state-interaction (CASSCF/MS-CASPT2/SO-RASSI) quantum-chemical approach and atomic-natural-orbital relativistic-correlation-consistent (ANO-RCC) basis sets. Several analyses of the methodology were carried out in order to reach converged results and therefore to establish a highly accurate level of theory. Good agreement is found with the experimental data with errors not higher than around 0.1 …
Ab initio quantum-chemical computations of the absorption cross sections of HgX2 and HgXY (X, y = Cl, Br, and I): Molecules of interest in the Earth's atmosphere
13 pags., 4 figs., 2 tabs.
Photochemistry of HOSO2 and SO3 and Implications for the Production of Sulfuric Acid
9 pags., 5 figs.
Photodissociation Mechanisms of Major Mercury(II) Species in the Atmospheric Chemical Cycle of Mercury
7 pags., 4 figs.
Iodine emissions from the sea ice of the Weddell Sea
Iodine compounds were measured above, below and within the sea ice of the Weddell Sea during a cruise in 2009, to make progress in elucidating the mechanism of local enhancement and volatilisation of iodine. I<sub>2</sub> mixing ratios of up to 12.4 pptv were measured 10 m above the sea ice, and up to 31 pptv was observed above surface snow on the nearby Brunt Ice Shelf – large amounts. Atmospheric IO of up to 7 pptv was measured from the ship, and the average sum of HOI and ICl was 1.9 pptv. These measurements confirm the Weddell Sea as an iodine hotspot. Average atmospheric concentrations of CH<sub>3</sub>I, C<sub>2</sub>H<sub>5</sub>I, CH&l…
Photoreduction of gaseous oxidized mercury changes global atmospheric mercury speciation, transport and deposition
9 pags, 8 figs. -- Correction autor: https://doi.org/10.1038/s41467-022-28455-w http://hdl.handle.net/10261/268181
Gas-Phase Photolysis of Hg(I) Radical Species: A New Atmospheric Mercury Reduction Process
The efficient gas-phase photoreduction of Hg(II) has recently been shown to change mercury cycling significantly in the atmosphere and its deposition to the Earth's surface. However, the photolysis of key Hg(I) species within that cycle is currently not considered. Here we present ultraviolet-visible absorption spectra and cross-sections of HgCl, HgBr, HgI, and HgOH radicals, computed by high-level quantum-chemical methods, and show for the first time that gas-phase Hg(I) photoreduction can occur at time scales that eventually would influence the mercury chemistry in the atmosphere. These results provide new fundamental understanding of the photobehavior of Hg(I) radicals and show that the …
In situ detection of atomic and molecular iodine using resonance and off-resonance fluorescence by lamp excitation: ROFLEX
17 pags, 11 figs, 4 tabs